Multiverses

July 20, 2011 • 8:54 am

I’m busy preparing for my trip, and so will have to send you around a bit the next few days. Worth reading today is Jason Rosenhouse’s take on multiverses: the idea that there could be more than one universe.  Jason was stimulated by an article in Scientific American about the concept (sadly, not free in its entirety), and responses by physicists by Alexander Vilenkin and Max Tegmark defending the possibility of multiverses (fortunately, free here).  A few years ago, having talked to several physicists about the idea, I wrote about it in The New Republic:

The idea of multiple universes may seem like a desperate move–a Hail Mary thrown out by physicists who are repelled by religious explanations. But physics is full of ideas that are completely counterintuitive, and multiverse theories fall naturally out of long-standing ideas of physics. They represent physicists’ attempts to give a naturalistic explanation for what others see as evidence of design. For many scientists, multiverses seem far more reasonable than the solipsistic assumption that our own universe with its 10,000,000,000,000,000 planets was created just so a single species of mammal would evolve on one of them fourteen billion years later.

It’s important for all of us to at least become acquainted with this theory because, as Jason points out, it has theological implications—not only about whether our planet is the special object of God’s attention, but because multiverses are relevant to the “fine-tuning” argument for God beloved of religious scientists.  Theologians often sneer at the multiverse theory as a ploy atheistic physicists to reject what they see as strong evidence for God. That’s why it’s important (beyond simply keeping up with exciting ideas in cosmology) to know why physicists posit multiverses, and to see that the idea is not something scientists concocted to get around the fine-tuning arguments.  And, as Rosenhouse notes:

And let us not forget that the God hypothesis, which is, after all, the preferred alternative of Haught and Polkinghorne, also puts forth a speculative, unobservable entity without a trace of experimental support. The multiverse hypothesis at least arises as a natural consequence of certain theories that have a sound, evidential basis. The God hypothesis is just invented from whole cloth, and is supported solely by philosophical gobbledygook like the cosmological argument.

Vilenkin and Tegmark discuss the science, and Rosenhouse goes after the theology.  They’re all short pieces, so do read them.

Speaking of the cosmological argument, if you can stand any more Edward “You-Can’t-Understand-It-Until-You’ve-Read-Dozens-of-Books” Feser, he has a new post on the subject,”So you think you understand the cosmological argument?”  We don’t, of course, for we haven’t read Feser’s two books on the topic.  As Feser says, “while the basic structure of the main versions of the argument is fairly simple, the background metaphysics necessary to a proper understanding of the key terms and inferences is not.”  Oy gewalt!

116 thoughts on “Multiverses

  1. One small quibble: I understand that the mulitiverse hypothesis is implied by some well-established physics theories, as Jason mentions in his article. As such it isn’t a Hail Mary pass at all — it’s a scientific hypothesis, grounded in already-established theories, which we are not yet able to test.

    As you point out, even a Hail Mary would be more probable than the scenario that this vast universe was created just for us humans.

    1. Tegmark’s remark: ‘Remember: Parallel universes are not a theory–they are predictions of certain theories.’

      1. Let’s not confuse the propositions of parallel universes and multiple universes. The notion of parallel universes was proposed to explain certain paradoxes of quantum physics (e.g. the 2 slit problem and quantum entanglement). The notion of multiple universes was proposed to explain the apparent fine tuning of certain physical constants.

        The difference is that, in multiple universes, each one is proposed to have different values for the physical constants, with the universe we occupy having the right set of values that are conducive to life. In parallel universes, the values of the set of physical constants would be the same for all of them.

  2. I don’t understand the cosmological argument? Apparently theologians don’t understand the cosmological argument and how it equivocates between universe and existence. This format of the universe after the big bang can be shown to have come into existence in the same sense as a baby comes into existence, but all of existence itself can’t be shown to have come into existence, and a divine creator supposedly created EVERYTHING.

    1. Yup.

      Once again, set theory to the rescue!

      “Existence” is the set of all that ever is, was, or will be.

      “To create” means to cause something to exist now that had not existed prior.

      In order for “God” to create existence, then there must be a point in time where nothing at all exists. But this would mean that “God” also doesn’t exist….

      You then quickly come back to special pleading of all sorts. “God” is equivalent to “existence.” (But what sense does it make to say that “existence” was tortured for a morning on a cross in first-century Judea?) “God” is outside of existence — but that somehow doesn’t mean that “God” doesn’t exist. “Existence” means all of everything except for “God” — which case we need a new term for the union of the sets labelled “existence” and “God”…and substituting said set for our original “existence” leads us right back where we started.

      When every possible way of looking at something keeps leading you back to a contradiction…well, at some point a rational person will at least pretend to entertain the thought that the something in question is a married bachelor….

      Cheers,

      b&

      1. Isn’t “being” philosophically distinct from “existence” nowadays?

        I’m thinking of the assertion that “existence” is that which stands between “being” and “nothingness”.

        I have no idea how such concepts stood before Heidegger and Sartre, though. I always thought that “existing” and “being” were pretty much the same thing.

        1. I have no clue what shades of invisible blue the philosophers are trying to paint words these days, which is why I fall back to set theory any why I defined my terms as I did.

          If a philosopher or theologian cares to define those terms in a coherent way that doesn’t lead to a contradiction when considering the possibility of a “first cause” or “unmoved mover” or whatever…well, good luck, and do please be sure to show all work.

          Cheers,

          b&

        2. Might not be a good idea to dwell too much on what turgid Germans and their French followers said with indo-European provincialism.

          Anyway, the essential points are clear:
          1) The big bang is the origin of the local hubble volume
          2) When people say “creation out of nothing”, they really don’t mean it
          3) The fine-tuning arguments are *bad*

        3. It sounds like where your getting at is,simply because you observe, it exists. By some how thinking that it is, because we think it is. As if we were to say that a floting mass of energy gained consciousness and that’s what we are right now. Like in a parallel universes there would be many senarios, which just that bringing huge amounts of possibilitys, that would increase change.

          But it seems I went off on another theory. Only the part about observing making what is, was where I was getting at.

      2. Ha, exactly. The religious are so prone to special pleading. But they need to realize that we are arguing over what the cause of existence (if anything) is and when they make their hypothesis exempt from the rules that everyone else has to follow their argument collapses.

    2. Speaking of “the big bang” theory, the TV show of that name did an opening send-up of the multiple universe idea this season.

      The show’s two biggest/brightest & therefore socially inept characters — Emmy winner Jim Parsons and former child star Mayim Bialik (Blossom) — attend, for fun, an author’s event at their local bookstore (clearly fiction, based on this anachronism).

      The book is portrayed as science-lite, while the actor who plays the author is Brian Greene, PhD (Columbia U physicist and child prodigy himself, like the Jim Parsons character). The segment cites some evolutionary biology as well. A sing-along is provided at the end.

      As this won’t pass muster at YouTube, here’s a link to a clip from The Big Bang Theory that aired 7 April 2011:
      http://www.hawksaloft.com/110720.html

  3. presumably the divine creator exists (hypothetically) before existence, which shows just how absurd the argument is.

  4. Yes, this is yet another attempt to get us to shut up by claiming we don’t have the intellectual grounding to understand the arguments.

    Didn’t work with Dr.Dr.Dr. Pigluicci, ain’t gonna work here.

    And no, I’m not going to buy your books. If Aquinas himself wasn’t able to convince me (and he didn’t), what makes you think that you’re any more prepared to overcome the obvious faults of each and every one of the 5 Ways?

    Shorter answer: Even if you accept EVERY premise, the CA still doesn’t work, because you have to then LEAP from “unmoved mover”, “first cause”, etc. to someone named Yahweh and baby Jesus. It’s a moronic assertion, one that Pastafarians everywhere decry as heresy.

  5. “while the basic structure of the main versions of the argument is fairly simple, the background metaphysics necessary to a proper understanding of the key terms and inferences is not.”

    It’s like quantum mechanics. It’s hard to understand at first, but once you study it, you come to accept that it really is true. To make someone a believer, all you have to do is teach them the physics.

    The cosmological argument works the same way, right Mr. Feser? Once you teach people the ins and outs, the vast majority come to agree that the argument is sound?

    Wait, you mean it doesn’t work that way?! People look at the evidence and still claim you’re mistaken?

    That’s odd.

    1. …and, of course, it must be pointed out that Feser is complaining because Dr. Coyne is reading theology to (GASP!) get a better grounding in theological arguments.

      His complaint seems to be “you’re not reading my book. Wah!”

      It would help if he weren’t tied to arguments that were thoroughly fisked at least 200 years ago. But such is the pace of progress within the Catholic Church. After all, they only just recently got around to “forgiving” Galileo.

      1. Feser is complaining because Dr. Coyne is reading theology to (GASP!) get a better grounding in theological arguments.

        No. He’s complaining because Coyne is getting help from a *gasp* Protestant *gasp* ex-priest.

  6. Feser says, “while the basic structure of the main versions of the argument is fairly simple, the background metaphysics necessary to a proper understanding of the key terms and inferences is not.”

    Edward Feser is an unregenerate obscurantist.

    At one point in his book “The Last Superstition” he argues by appealing to the large number of books he has on his bookshelf, and to the fact some of those books are really really long! It’s adorable.

    Yes, it is true that these Dark Age monks spilled gallons of ink on this made up “metaphysics”, and from that construct elaborate arguments. But so what? We have thousands of volumes on astrology and homeopathy too.

  7. I’ve been reading The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, by Brian Greene.

    It details actually several different (and not mutually exclusive) multiverse scenarios. Some seem pretty solid to me. (Not sold on the brane one, but I ain’t no quantum physicist.)

    One idea was that our universe is one of infinite “bubble universes” all of which may have different universal laws. It’s been such a long slog through the book I actually have forgotten the details. (Guess I have to finish it so I can begin rereading it.)

    1. I found the book to be heavy going, but enlightening. I am a physicist by education, but many of the ideas were new to me. I havent’ kept up with cosmology in the last 15 years or so, and it’s apparent that there have been huge developments. There is a suggestion in some articles that the multiverse hypothesis has been cooked up to answer proponents of the “fine tuning therefore god” hypothesis, but this assertion seems to me to be groundless, as others here have pointed out.

      1. Ahhh, nice to hear it’s “heavy going” from a physicist.

        I’ve read my fair share of popular science physics, but this is one of the hardest I’ve encountered. A Brief History of Time was nuttin.

    2. Yes, several theories. And agreed on the brane one, but I’m no theoretic physicist either.

      Bubble universes comes out of general relativity cosmological solutions of simple models.

      Basically these models have a cosmological constant (CC) that can be identified with the dark energy of standard cosmology. Since different universes can have different parameters, they will have different CC (say). Hence they can create stacked bubbles of universes with different properties.

      [If you will you can think of the CC as a potential. All universes wants to minimize it (flatten out). This is why one universe can spontaneously generate a bubble of locally lower potential.

      Luckily our universe has nearly succeeded (low CC). Or there would be a high likelihood for a spontaneous bubble sweeping in and erasing our old universe.]

      This can be developed further to adopt string theory into cosmology et cetera, with an increasing number of specialist language. Or, as you may guess, about here is where I opt out further study. 😀

    1. This not possible.

      Feser, in the post to which Dr. Coyne has linked, has used every word in the OED. Every word. Many of them, twice. It is a staggeringly long post.

      There are many comments, too. By all means, skip every other one, as the comments are all written by the same 5 people, who are posting about what dummies we are.

  8. “…assumption that our own universe with its 10,000,000,000,000,000 planets was created just so a single species of mammal would evolve on one of them fourteen billion years later.”

    Exactly.
    And not to mention that 99.9^500 power % of the universe is NOT fine-tuned for life makes it even sillier.
    Like I’ve been saying, if someone thinks the universe is “fine-tuned” for life because of our 1 tiny planet, then I could say that finding only 1 square millimeter of wood on the entire planet would mean the planet is fine-tuned for termites.

  9. I thought the idea of the multiverse was not motivated by repellance to theological explanation, but is a direct result of String Theory which allows it.

  10. Reading Feser reminds me of one of my favorite quotes (from John Maynard Keynes, who collected many of Newton’s writings):

    “Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind which looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10,000 years ago… He looked on the whole universe and all that is in it as a riddle, as a secret which could be read by applying pure thought to certain evidence, certain mystic clues which God had laid about the world to allow a sort of philosopher’s treasure hunt to the esoteric brotherhood… he was almost entirely concerned, not in serious experiment, but in trying to read the riddle of tradition, to find meaning in cryptic verses, to imitate the alleged but largely imaginary experiments of the initiates of past centuries… I have glanced through a great quantity of this at least 100,000 words, I should say. It is utterly impossible to deny that it is wholly magical and wholly devoid of scientific value; and also impossible not to admit that Newton devoted years of work to it.”

    1. That’s a great quote about Newton. It is also somewhat depressing. All that wasted effort! Thomas Aquinas wrote over 8 million words. I am reminded of this from Sam Harris, commenting on a Catholic meeting to discuss Limbo:

      “Can we conceive of a project more intellectually forlorn than this? Just imagine what these deliberations must be like. Is there the slightest possibility that someone will present evidence indicating the eternal fate of unbaptized children after death? How can any educated person think this anything but a hilarious, terrifying, and unconscionable waste of time? When one considers the fact that this is the very institution that has produced and sheltered an elite army of child molesters, the whole enterprise begins to exude a truly diabolical aura of misspent human energy.”

      Sure, read a book or two by Feser or whatever apologist you care to. There is some value in that. But spend years, like Feser has, slogging through 8 million words of Aquinas? Truly a diabolical waste of human energy. I cannot conceive of a project more intellectually forlorn.

      1. Imagine doing that and one day waking up to the realisation that it was all a waste of time. Talk about a mid-life crisis!

        1. Feser’s extremely arrogant and defensive tone suggests to me that this realisation may be dawning on him already. The level of hectoring and sneering in his posts looks like the frenzied activity of someone who is even more concerned to convince himself than anyone else. This level of defensiveness is usually associated with denial.

        2. If Feser indeed has wasted his life in a useless field of study, the least we can do is to let him look down on the rest of us.

          I mean, what else has he got?

          Would it hurt us, I wonder, to gather a few laurel leaves?

  11. So has any theologian explained, or even thought of the question, how the “void” that god created from was perfectly fine-tuned to allow for a god that can create a fine-tuned material universe?

    That fine-tuned void that allows for a god is incredibly more unlikely to me than purely material explanations for our material universe. Again, the god hypothesis introduces infinitely more problems than it solves!

  12. I tend to look on the multiverse theories in much the same way I look on the supernatural, and god, hypotheses:

    If they interact with our ‘universe’ then they’re part of our universe. Or rather we’re all part of the same universe.

    If they do not interact with our universe then that is the same, functionally, as not existing.

    Mike.

    1. It will possibly lead to an explanatory framework which may be testable or which will point theorists in the direction of an overarching theory

    2. Yeah, I think this is a word-thing. Polysemantism to the rescue! Multiverse-theory just refers to distinct space-time blobs as “universes”, no?

  13. Cosmologists are proposing versions of the multiverse to not ONLY account for fine tuning, but also to provide a framework for ‘explaining’ the double slit experiment, the inflationary big bang model & any number of other observations about our reality.

    Most cosmologists don’t care one fig what theologians are claiming. The theological world view is so…

    paltry, limited & laughably human-centric

  14. Multiverses can’t do anything with the fine tuning “problem”. There have to be meta-laws describing when and how new universes form, and how the laws of physics change between them. The fine tuning just gets kicked up into the meta laws.

    Nothing to see here.

    1. Ha! Someday in the future they’ll be saying, “Sure, you’ve proven beyond a reasonable doubt that our universe is just one of many millions of non-life-sustaining universes. But! The conditions of the meta-verse are fine tuned to eventually create a universe that would eventually create a planet that would eventually develop life that would eventually become God’s chosen people. If meta-verse constant X were only 0.0001% different, it would never have been able to spawn a universe like ours!”

      1. Or they can do it the simple way:

        Millions of Universes?? Why, now there must be a God!!!!

        One universe is just not all that impressive. But lots and lots of them surely requires an intentional agent who loves to deliberately create universes. It’s the most parsimonious explanation.

        Heads they win; tails we lose. Apologetics are such fun. Anyone can do it.

        1. Yes, I’ve thought much the same thing.

          Intelligent aliens who have never heard of god or Jesus? We’re the special ones god chose to convert the godless aliens.

          No discernible intelligent life anywhere else in the universe? See how much god loves us? He (obviously a male) created the whole universe just for us!

          And on and on.

          Karen Armstrong seems to be the most guilty of this form of thinking. No evidence at all for a god? Well, isn’t that the most godly thing a god can do? Hide for all eternity?

      1. First, it’s important to realize the “fine tuning problem” is just a rhetorical game where you say “Why is the world like this and not like that? God must have made it so.” The “problem” exists only in christian apologetics, not in science, which is why people studying things like the multiverse have to get their funding from private sources like the Templeton Foundation rather than the NSF.

        Second, multiverse proponents are loath to sully themselves with things like rigor and evidence, so it’s harder than it might be to give a specific example.

        But take the theory that Dawkins promoted where new universes are created inside black holes. This theory can’t explain the existence of black holes in the first place (not just any black holes, but the special kind that have new universes inside them with slightly different laws or constants or whatever), so there’s your fine tuning.

        So far as I can see, the only alternative to being susceptible to fine tuning is to be the one and only one logically possible theory of everything. But there’s no reason to suppose that such a theory even exists.

        1. I agree that religious finetuning (sensitive parameters suitable for observers) is wholly separate from physical finetuning (why parameters that are unnatural in the theory, i.e. not ~ 1) or cosmological finetuning (why parameters allowing observers now).

          And in fact religious finetuning is rejected by evidence, according to Stenger’s research ~ 50 % of parametrically nearby universes have stars.

          But it is also a matter of fact known from Weinberg, Bousso and others that anthropic/environmental selection on multiverses solves some of physical and all of cosmological finetuning.

          And no philosophical “meta laws” are used, but these results follows from the theories combined with _absence_ of other selection principles, such as uniqueness et cetera. All selection is according to stochastic distributions, whatever they can be. And it is self-consistent. (Btw, here 6 finetuned parameters are predicted and tested OK. Standard cosmology manages merely 5!)

        2. That was Lee Smolin’s theory. Black holes are formed in the normal way by massive stars collapsing in its own gravity. The theory just says that black holes may possibly create wormholes to other universes. Einstein’s wormhole idea connects one part of the universe to another part. This is a variation in suggesting that the other side of the wormhole could be a universe governed by different laws. The explanatory power of the idea lies in the evolution of universes so to speak. Only universes with black holes can “beget” other universes, so you would expect this type of universe to be prevalent just because those without black holes would be dead ends. It just so happened, the same conditions that allow for the creation of black holes (and stars) also allow for the emergence of life.

          1. Since Smolin proposed his theory, so called white holes (with or without wormholes out of black holes) have more or less been rejected.

            The theory is dead within the community, is my understanding.

  15. I strongly recommend Brian Greene’s latest book:

    * Greene, Brian. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011.

  16. “That’s why it’s important (beyond simply keeping up with exciting ideas in cosmology) to know why physicists posit multiverses…[etc].”

    You are setting us homework while you are away?! Will there be a test?

  17. How long, I wonder, until the theists latch on to the multiverse idea for their own purposes, like they have with quantum theory? They love non-testable “scientific theories” which have little or no connection to obsevations and cannot be refuted.

    1. I saw that a few weeks back. Can’t remember the circumstances though. But _clearly_ the ability to beat finetuning points to a creator! [/snark]

  18. Feser’s version of the cosmological argument is provably wrong:

    What defenders of the cosmological argument do say is that what comes into existence has a cause … You may disagree with the claims – though if you think they are falsified by modern physics, you are sorely mistaken

    Anyone with passing familiarity with physics can see this for themselves. For example, here is Feynman in his popular QED on the causality of creation in physics (p. 58f, emph. mine):

    quantum electrodynamics, which looks at first like an absurd idea with no causality, no mechanism, and nothing real to it, produces effects that you are familiar with: light bouncing off a mirror, light bending when it goes from air into water, and light focused by a lens. It also produces other effects that you may or may not have seen, such as the diffraction grating and a number of other things. In fact, the theory continues to be successful at explaining every phenomenon of light.

    Feser should acquaint himself with with these basic physical facts before making grandiose, incorrect statements about causality. As an exercise, he can start with explaining to us the causality of electron-electron repulsion, or beta-decay, both represented by these Feynman diagrams:

    https://secure.wikimedia.org/wikipedia/en/wiki/File:MollerScattering-t.svg
    https://secure.wikimedia.org/wikipedia/en/wiki/File:Beta_Negative_Decay.svg

    As a defender and author of two books on the cosmological argument, perhaps Feser can tell us in a paragraph or less what causes the creation of a photon? What cause the creation of a positron-electron pair? What causes the creation of a W boson? Causality is meaningless in the context of the physical description of these objects, and this is the context that describes our everyday reality to almost one part in a billion billion. Feser includes Feynman’s photo and anecdotes in a post about physics, but ignores Feynman’s physics, which make mincemeat of Feser’s notion of causality and the cosmological argument.

    If Feser does step up and explain what creates a photon and the rest, be sure to compare his answer to Feynman’s, again from QED, p. 92f:

    let’s calculate the probability that two electrons, at points 1 and 2 in space-time, end up at points 3 and 4 (see Fig. 59). … To make a more exact calculation that will agree more closely with the results of experiment, we must consider other ways this event could happen. For instance, for each of the two main ways the event can happen, one elec­ tron could go charging off to some new and wonderful place and emit a photon (see Fig. 60). Meanwhile, the other electron could go to some other place and absorb the photon. Calculating the amplitude for the first of these new ways involves multiplying the amplitudes for: an electron goes from 1 to the new and wonderful place, S (where it emits a photon), and then goes from 5 to 3; the other electron goes from 2 to the other place, 6 (where it absorbs the photon), and then goes from 6 to 4. … But wait: positions 5 and 6 could be anywhere in space and time—yes, anywhere—and the arrows for all of those positions have to be calculated and added together. … I would like to point out something about photons being emitted and absorbed: if point 6 is later than point 5, we might say that the photon was emitted at 5 and absorbed at 6 (see Fig. 61). If 6 is earlier than 5, we might prefer to say the photon was emitted at 6 and absorbed at 5, but we could just as well say that the photon is going backwards in time! However, we don’t have to worry about which way in space-time the photon went; it’s all included in the for­mula for P(5 to 6), and we say a photon was “exchanged.” Isn’t it beautiful how simple Nature is!

    1. Steve:

      Just a quick question from someone with an amateur familiarity with quantum theory and particle physics: At the level of decay that you describe, is there anything happening prior to and nearby the particles that ultimately decay? Is there energy around them, forces around them, other particles around them, real or virtual?

      I could see your point if there was absolutely nothing existing prior to and surrounding the particle that decays except for the particle that decays, but it seems that there is a lot going on around the decaying particle, and that all those forces, energies and particles might result in the very instability that makes the particle decay in the first place.

      An uncaused event would have to be an ex nihilo event, i.e. caused by absolutely nothing at all. It seems that there are a number of causal influences acting upon those particles that decay, and that although none are determinate, it does not necessarily follow that none are doing anything at all to influence the decay.

      It might be the case that we just do not know how the antecedent conditions combine to result in the decay, but it does not follow that they are not doing anything at all.

      Any thoughts?

      1. is there anything happening prior to and nearby the particles that ultimately decay?

        No. Feynman answers all these questions, so I’ll just parrot him from QED, pp. 18f:

        Another possible theory is that the photons have some kind of internal mechanism-“wheels” and “gears” inside that are turning in some way-so that when a photon is “aimed” just right, it goes through the glass, and when it’s not aimed right, it reflects. … The trouble with that theory is, it doesn’t agree with experiment … Try as we might to invent a reasonable theory that can explain how a photon “makes up its mind” whether to go through glass or bounce back, it is impossible to predict which way a given photon will go. Philosophers have said that if the same circumstances don’t always produce the same results, predictions are impossible and science will collapse. Here is a circumstance—identical photons are always coming down in the same direction to the same piece of glass—that produces different results. We cannot predict whether a given photon will arrive at A or B. All we can predict is that out of 100 photons that come down, an average of 4 will be reflected by the front surface. Does this mean that physics, a science of great exactitude, has been reduced to calculating only the probability of an event, and not predicting exactly what will happen? Yes. That’s a retreat, but that’s the way it is: Nature permits us to cal­culate only probabilities. Yet science has not collapsed.

        There is no “cause” for the creation of a photon (or W boson or electron or quark or any physical particle), and causality doesn’t even make sense in the context of quantum field theory, in which particles can traverse any continuous path in space-time, forward or backward in time, in or out of the light cone.

        1. Steve:

          >> No.

          So, there are no surrounding particles, no energy or forces operative? It seems that nothing exists except a single subatomic particle. Is that what Feynman is saying?

          >> There is no “cause” for the creation of a photon (or W boson or electron or quark or any physical particle),

          But is that because the causal factors are too numerous, each of which is exerting a miniscule effect? There is no cause for a dice landing on 6, but that is not because there are no antecedent causes, but because there are too many, e.g. air resistance, rotational energy of the dice, force of gravity, and so on.

          1. there are no surrounding particles, no energy or forces operative? … Is that what Feynman is saying?

            No. Yes (QED, pp. 85f):

            I present to you the three basic actions, from which all the phenomena of light and electrons arise.
            –ACTION #1: A photon goes from place to place.
            –ACTION #2: An electron goes from place to place.
            –ACTION #3: An electron emits or absorbs a photon.
            Each of these actions has an amplitude—an arrow—that can be calculated according to certain rules. In a moment, I’ll tell you those rules, or laws, out of which we can make the whole world

            All you need to know to describe the entirety of the reality in front of you is how to compute the probabilities of electron-photon couplings. And there is no such thinh as “force”—this a classical term for what we now “know” (tested to one part in a billion billion) to be particle-particle interactions. That’s what Feynman is saying.

            A used copy will set you back $1.76.

          2. Steve:

            There are two main problems that I have with your line of reasoning.

            First, take the example of flipping a coin. One can calculate the probability of the coin landing on heads or on tails. This probability calculation is incredibly accurate. According to your line of reasoning, it follows that this is an uncaused event. This is clearly untrue, because the coin is affected by a number of causes prior to landing on either heads or tails. So, the fact that a probability calculation can be incredibly accurate in predicting the probability of outcomes does not imply that the ultimate event is uncaused in the requisite sense of being an ex nihilo event.

            Second, take the example of Newtonian mechanics. This model of motion of macroscopic bodies is incredibly accurate in its respective domain. It does not make any mention of the atoms that compose the physical bodies that are involved. According to your line of reasoning, because it is a highly successful scientific model, if it is silent about atoms, then it follows that atoms do not exist and are not involved. This clearly does not follow, and if it does not work in this case, then it cannot work in your case. After all, just because QM makes no mention of specific antecedent causal conditions does not necessarily mean that there are no antecedent conditions.

            From what I understand, QM seems to prohibit ex nihilo events altogether. Even in a vacuum, there is energy, and thus there is always something causing something else to happen. There is never absolutely nothing, and thus there is no such thing as an uncaused ex nihilo event, even in QM. However, perhaps someone who knows QM in depth would be able to speak to this issue better than I can.

          3. That is correct physics.

            The problem is the shoe on the other foot, because according to theology/philosophy there should always be nearby (“immediate”) causes. Physics causality out of process doesn’t fit that naive (and falsified) picture.

            The run around you get is that causality is not clearly defined for all purposes, which is correct. It is an outcome of relativity, and relativity isn’t always easy. For example there is no general time in general relativity.

            As it happens FLRW universes like ours can get a global time arrow by its expansion. (Think of onion layers, each a result of a certain cosmological age. This is what we measure as cosmological redshift.)

            But all this tells us that causality is not simple, and that the argument that causality “should be simple (when clearly defined)” is always wrong.

  19. I twitch in suppressed rage when the “fine-tuning problem” comes up.
    When physicists talk about fine-tuning, they do not mean “made suitable”, it means there is currently no knowledge of an a priori reason why certain parameters take the values they do – they have to be put in from experimental results. This is fine – free parameters arise in many places in maths (if a theory involves straightforward derivatives, the theory might predict the value of the derivative of a function, but the function itself can differ from the integral of this up to a constant, say). It is the theory that is fine-tuned then, not the universe.
    Furthermore, the universe as a whole is clearly not “made suitable” for life (as other commenters have already pointed out, I know) & no reason to suggest that the fundamental parameters of the universe are such that they are in order for life to arise – life could not have arisen if the parameters (which were set 14 BILLION years ago!) were unsuitable. The claims about the impossibility of life to arise if the parameters differed by 3 parts in an elephant are not necessarily true (as Victor Stenger has written about) & even if they were – life as we may know it may not have arisen but it’s not to say that some other replicating/metabolising construct would not have arisen!
    /rant.

    1. True that in practice finetuning (“unnatural” parameters) can require measurement. But they can also come from new theory. (Which is always the theorists hope, natch.)

    1. Multiverses within multiverses. Tegmark lists 4 types that are layered within one another.

      Or you could take a stack of (non-intersecting) bubble universes, think onion, as one multiverse. Several such sets within a larger universe becomes “multiverses”.

      It is mostly a definitional issue. Physicists use Occam’s razor – “a multiverse”.

      1. If we need a name for the object containing all these multiverses, I go for “Multiplexiverse”. Hopefully, there’ll only be one of those!

    2. The original terminology, which I believe still makes the most sense, is that by definition, there’s one universe. We can observe, and indeed influence, only one of the multiverses it’s made out of.

      Someone came along later and reversed the definitions because “multiple universes”, like “splitting the atom”, sounds cool, even if it’s technically a contradiction in terms (not that that makes nuclear technology any less real, of course, no matter how pedantic you are).

      1. Well, yes. But physicists aren’t nearly as inclusive in their theories as biologists are.

        Nor are they especially exclusive as not everyone are on board with testing as primary and it would be unpractical if relentlessly pursued.

        So you could still argue “unnecessary”. It all concerns a social, and somewhat practical, thing.

  20. Basic logic is sufficient to discard the ‘cosmological argument’ – a theory of multiverses is not at all necessary to show the cosmological argument for the colossal load of crap that it is.

  21. I asked some questions over at EvolutionBlog, but you all seem to be better at providing answers, so if I may:

    Isn’t the fine tuning argument BS to being with? It’s my understanding that even if the universe is fine-tuned to support life, we are a biased sample because we would have to be alive to think about it. Further, improbable stuff happens all the time, and we don’t even know the prior probability of getting our universe, so our universe is either not improbable, or it is but that doesn’t mean it couldn’t happen.

    In other words, the multiverse hypothesis is completely unnecessary in answering the fine-tuning argument, cause it’s a shit argument.

    Have I gone wrong somewhere?

    1. I think that’s one of the versions of the anthropic principle (weak, strong, or somewhere in between). Victor Stenger has written extensively about the fine-tuning argument, and you can find some of his stuff on the web. He just produced a new book “The Fallacy of Fine-Tuning” which I’m trying to find in book shops.

  22. Holy shit. If multiverses do exist then out there may exist a Jerry Coyne who “chose” to be a rabbi and run a website called “Why Revelation is True”.

    1. Even if ours is the only universe but it’s infinite, there’s also a madamX out there who also chose to be a rabbi (unless you’re already a rabbi).

      1. Once you start throwing out the concept of infinite extant possibilities, it’s easy to wreak havoc with probabilities…the predicted probabilities look nothing like the observed ones.

        Whatever infinities may (or may not) actually exist, we can be certain that they’re bounded in some fashion.

        Cheers,

        b&

        1. Can we be certain of this? I’m no expert in the field, but I did read Max Tegmark’s older article in Scientific American where he claims, “There are infinitely many other inhabited planets..that have people…who play out every possible permutation of your life choices.”

          1. Try a thought experiment.

            From a “God’s eye” perspective, tally up all the universes. Calculate the number of universes in which random events come out according to well-defined statistical results, and compare them in which all those random events come out in some disjointed non-sensical form of noise.

            You’ll find a nice Bell curve, with the overwhelming number of universes being entirely chaotic, with no rhyme, reason, or statistical predictability. And the odds that you actually find yourself in a comprehensible universe are incomprehensibly small.

            You know those “what if” games where you speculate about all the air molecules in the room, as part of their random walk, migrating to the corner therefore suffocating you? Well, in the infinite universes theory, that’s constantly happening in every room in an infinite number of universes.

            We don’t see that happening, so we can conclude that at least a simple form of “everything possible always happens in a universe somewhere” is false.

            Cheers,

            b&

          2. I understand your point now, and I’m not saying (and neither is Tegmark) that absolutely everything that can be thought of is possible. For example, I suspect that there is no part of the single infinite universe where I create a perpetual motion machine. However, the example of Jerry Coyne or you or madamX or me being a rabbi is possible, but perhaps rather remote. Anyway, Tegmark suggests that we’ll never meet Rabbi Coyne, so at the moment, with our current state of knowledge, we can only speculate.

          3. But you still have an infinite number of universes with Professor Coyne and an infinite number of universes with Rabbi Coyne. And those two infinities are both countable, and therefore the same size. The odds are 50 / 50.

            Except that there’s also an equally-infinite number of universes with Father Coyne. The odds are 33 / 33 / 33.

            Make that Imam Coyne — and so on, and all these infinite numbers of variations on poor Jerry are the exact same size of infinity.

            The only way you get different sizes of infinities is when you move beyond the rationals into the reals (and beyond), and that hardly leads itself to weighted probabilities.

            It should start to become apparent, therefore, that there is but a finite number of universes with a Jerry Coyne in them.

            Cheers,

            b&

          4. I think I ran out of reply space, but the last example seems to talking about higher order universes, infinite in number. I’m only talking about the “simple” case of one universe but infinite in extent.

  23. There is one thing that is perfectly clear: If, in the future science is able to conclusively show, through clear, repeatable, undeniable evidence, that multiverses exist, then the religious establishment will claim that truly it manifests the greatness and glory of god that he formed the multiverses. Scientists were just a bit slow in picking up on it.

  24. One of the things that I have thought about ever since I was a young boy is if there are indeed intelligent extraterrestrial life forms, will they have religion, or will they take a more Marlovian viewpoint where they “count religion but a childish toy and hold there is no sin but ignorance”?

  25. I see no problem with the meatlaws that would prevent the creation of a good multiwurst.

    Say you used beef, lamb and pork. You might want to cut down on the lamb percentage so as not to overwhelm the pork and you might have to up the fat content to compensate for the beef if you used a lean cut.

    I would avoid cheesy solutions, though.

    Bread crumbs, powdered milk and black pepper (dark matter) should bind the multiwurst nicely.

  26. Well; are we supposed to accept that if there is a doG that wants ordinary people to know it and love it, it deliberately makes itself so obscure that 2000 years of excruciating theological wranglinhg is insufficient to elucidate its existence?

    1. Genesis, chapter 1, verse 1. It requires a bit of interpretational latitude, of course, but notice that the word is “heavens” not “heaven”. Simply interpret a “heaven” to be a single universe and there you have it.

  27. Thanks, I will read that.

    Meanwhile, a clarification:

    “But physics is full of ideas that are completely counterintuitive, and multiverse theories fall naturally out of long-standing ideas of physics. They represent physicists’ attempts to give a naturalistic explanation for what others see as evidence of design.”

    The first sentence is good. The next confuses anthropic/environmental selection on multiverses as explanation for physical finetuning with the actual existence of multiverses.

    Multiverses comes naturally out of inflation for instance, which is now (a not quite tested on its lonesome) part of the tested theory of standard cosmology. As such they represent properties of these theories.

    Anthropic/environmental selection on multiverses comes naturally out of the existence of multiverses with some form of distribution, as an estimate of (near) maximum likelihood that we find ourselves in universe with some parameters. As such they represent properties of stochastic distributions as they _may_ apply on the above theories.

  28. What problem does multiple universes purport to solve? Why isn’t the universe we already have–and haven’t even actually explored yet–big enough?

    1. See my comment just above yours!

      – Multiverses occurs naturally in the theories that we have now.

      – They solve physical finetuning in many (but not yet all) cases.

  29. Oh dear, I don’t know how Jerry could have missed this; I have now read it; and the unnamed author is George Ellis. George Ellis is a Quaker and 2004 Templeton winner:

    “George F. R. Ellis (2004)

    George F. R. Ellis is a theoretical cosmologist and Professor Emeritus of Applied Mathematics at the University of Cape Town, South Africa. He has investigated whether or not there was a start to the universe, if there is one universe or many, the evolution of complexity, and the functioning of the human mind, as well as the intersection of these issues with areas beyond the boundaries of science.”

    [Access to the article is free after registration with Scientific American:]

    I have long since dismissed Ellis, known cosmologist, on the specific issue of multiverses.

    The main tip off is his use of creationism and accommodationism.

    “Other options exist, too. The universe might be pure happenstance—it just turned out that way. Or things might in some sense be meant to be the way they are—purpose or intent somehow underlies existence. Science cannot determine which is the case, because these are metaphysical issues.” [My bold.]

    Which is pure humor, since he just criticized the idea of organizing principles because they would be “pure speculation” without “no way whatsoever to verify the existence or nature of any such organizing principle.”

    Further religious arguments is his claim that multiverses are entities that falls under Occam’s principle instead of the parameters of laws, something that Rosenhouse somehow mentions under theologians.

    Also his use of “proof” instead of test, and “where you there” instead of uniformity. I am not going to go into these now, especially since Tegmark answers them nicely.

    In fact Tegmark does an outstanding job in the light of his taking Templeton money for his FQXi Foundational Questions Institute that collects all sorts of thinkers and woo meisters including Templeton winners. He as much as point out that Ellis is espousing pure theology without naming it:

    “(1) and (2) appear to be motivated by little more than human hubris. The omnivision assumption effectively redefines the word “exists” to be synonymous with what is observable to us humans, akin to an ostrich with its head in the sand. Those who insist on the pedagogical reality assumption will typically have rejected comfortingly familiar childhood notions like Santa Claus, local realism, the Tooth Fairy, and creationism—but have they really worked hard enough to free themselves from comfortingly familiar notions that are more deeply rooted? In my personal opinion, our job as scientists is to try to figure out how the world works, not to tell it how to work based on our philosophical preconceptions.”

    1. I’ve just read Ellis’ article too and was gob-smacked when I got to the sentence which you pick out.

      Up to this point he makes a few sceptical points regarding the multiverse hypothesis. Then with a stab at the Occam gambit (his version would have junked the atomic hypothesis of matter) he dives into polemics.

      That the multiverse is the best explanation for the laws of physics being what they are is challenged by saying it all depends on what kind of explanation one is prepared to accept. A deus ex machina now makes a procrustean appearance. The mathematical implications of a model which is consistent with all known cosmological observations, is forced into the same speculative bed as “purpose or intent…” underlying “existence”. Then Ellis asserts that science cannot determine which is the case because these are metaphysical issues.

      Despite the fact that some multiverse models have been empirically tested and not been falsified and that string theory is capable of being falsified, the multiverse hypothesis belongs to the same epistemological species as intelligent design.

      “Scientists proposed the multiverse as a way of resolving deep issues about the nature of existence, but the proposal leaves the ultimate issues unresolved. All the same issues that arise in relation to the universe arise again in relation to the multiverse. If the multiverse exists, did it come into existence through necessity, chance or purpose? That is a metaphysical question that no physical theory can answer for either the universe or the multiverse.”

      The multiverse has been proposed as an attempt to simultaneously answer several questions relating to some specific features of the universe; viz: the big bang, dark energy and the form of the laws of nature. The multiverse is not an attempt to answer “ultimate issues”. Science has smaller fish to fry and yet still has the knack of revealing hidden aspects of nature beyond the dreams of metaphysical speculation. The multiverse hypothesis will be judged by its abiltity to predict and/or make sense of phenomena better than others. The God hypothesis will be judged according to whether or not one insists on its being true come what may.

  30. “I have long since dismissed Ellis, known cosmologist, on the specific issue of multiverses.”

    To be clear, I do this not only because religion ate Ellis brain way before his Templeton. I do think that his arguing about testability and existence instead of assuming them and find out will leave him, and similar physicists, in the dust.

    And then I don’t mean the dust that makes stars and life. 😀

  31. On a related topic (well, two related topics) – what’s the current status of the ekpyrotic universe? I read Turok and Steinhardt’s book, and throughout I had the lurking suspicion of, not a religious agenda, but sort of a maybe-vaguely-culturally-religiously-conditioned philosophical bias against the idea of an endlessly expanding universe as dreary and nihilistic (you know, in that awful cold, bleak, atheistic way religious people can’t stand).
    Which I found vaguely amusing as (related topic no. 2) I had previously read and loved “The Five Ages of the Universe” – and what’s the current status of that (i. e. has anything in it been particularly supported or discredited)?

    1. Needed disclaimer: I am an interested layman.

      – As I understand it, the idea of cyclical universes in general is in bad shape. I hear, but have not studied, that several results (of Bousso among others, I believe) makes them impossible. Note that “no go” theorems always are iffy since they have loopholes.

      The ekpyrotic universe, which doesn’t need to be cyclic, is in itself more or less rejected by WMAP later results, is what I hear. Again, haven’t checked that, unneeded if next to no one is supporting it anymore.

      I too read between the lines that at least Turok is dead set on this model. I didn’t know the reason though. Sounds like another Hoyle.

      – I have never heard of “The Five Ages”, but it looks to be the standard model extrapolation [from Wikipedia], before it was accepted and fine detailed with eras.

      It has been more accepted that inflation _replaces_ big bang in the standard cosmology.
      Inflation presages the later expansion which is the old big bang expansion and provides initial conditions for it.

      So there is a primordial era with (possible eternal inflation) – local volume inflation ends – freewheeling big bang with various degree of matter vs radiation content eras (lots of eras as structure formation happens) – later on dark energy accelerating expansion.

      Also people discuss how much matter the observable universe will contain as it nears the later ages. Dark energy seems to pull at the Local Group, so possibly clusters aren’t really gravitationally bounded. Then we would eventually see only a single galaxy in the universe, our own.

  32. We may now actually have some evidence (tentative) that other universes exist. This is called “dark flow”: large galaxy clusters are moving toward a specific region in space which is consistent with the idea that a nearby universe is attracting these galaxy clusters. If you Google “dark flow,” you’ll find a number of articles discussing the phenomenon. See what you think. I emphasize this is all “tentative” (more observations are required, different explanations exist for dark flow). Still, maybe scientists are on to something here. Beats theology.

    1. No, “dark flow” has repeatedly been rejected.

      Read the recent WMAP group on the absence of most anomalies people has claimed to see (but haven’t really if you use good statistics).

    2. Here is an amusing take and link to the paper:

      “Many of the reports of WMAP CMB anomalies would likely make for good teaching material, as they illustrate well the many traps that you can so easily fall into when doing after-the-fact (a posteriori) statistical analyses. Or, as the team puts it in regard to the Stephen Hawking initials: “It is clear that the combined selection of looking for initials, these particular initials, and their alignment and location are all a posteriori choices. For a rich data set, as is the case with WMAP, there are a lot of data and a lot of ways of analyzing the data.”

      And what happens when you have a lot of data? Low probability events are guaranteed to occur!”

      The latter is why particle scientists have to go to 5 sigma to even start consider “an observation”, as they churn out so many runs and analyses.

  33. I find that scientist are advocating in a conspiracy the multi-verse universe to avoid GOD. If this is true than all science can be called that. The concept of multi-verse arises as a natural consequence of String theory which if true allows for multi solutions to the ” describing bubble universes with diverse physical properties”.
    At present string theory is our best description of small scale structure. So theologians beat it to a retreat and try to find justifications of GOD within the multiverse.
    Multiverse is not as theologians contend to avoid the fine tune thesis. It does shows that after all string theory may have some truth in it.

  34. I’d actually consider the Feser’s note that “while the basic structure of the main versions of the argument is fairly simple, the background metaphysics necessary to a proper understanding of the key terms and inferences is not” a semi-reasonable observation. Similarly, the basic structure of the basis for the scientific method via Occam’s razor is fairly simple, but the background mathematics necessary to understanding the rigor isn’t.

    On the other hand, in the latter case it’s not hard to present the axiomatic assumptions and their primary undefinable terms. This doesn’t seem to be the case for the background metaphysics. As such, his note is only semi-reasonable.

  35. I have always thought that life as we know it is constrained by the history and nature of the universe. In the ‘Grand Design” Steven Hawking takes the view that our existence constrains the nature and history of the universe. it has to have been exactly what is needed for us to be here. Interesting point of view!

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